Impulse tool with bypass means



Nov. 8, 1966 R. P. GlLLlS IMPULSE TOOL WITH BYPASS MEANS 4 Sheets-Sheet 1 Filed March 22, 1965 FIG.

INVENTOR. 23M

AGENT ROBERT F.

1966 R. P. GILLIS IMPULSE TOOL WITH BYPASS MEANS I 4 Sheets-Sheet 2 Filed March 22, 1965 OPERATION WITHOUT DEVICE TIME (sen) V mmnwmwmm OPERATION WITH DEVICE Li -J TIME (sec) INVENTOR. ROHERT P GILL/S AGENT Nov. 8, 1966 R. P. GILLIS IMPULSE TOOL WITH BYPASS MEANS 4 Sheets-Sheet Z Filed March 22, 1965 INVENTOR. R055? 7' P GIL L/S AGENT Nov. 8, 1966 R. P. GILLIS 3,283,537

IMPULSE TOOL WITH BYPASS MEANS Filed March 22, 1965 4 SheetsSheet 4 ROBERT P G/LL/S AGENT United States Patent 3,283,537 IMPULSE TOOL WITH BYPASS MEANS Robert P. Gillis, Somerville, N.J., assignor to Ingersoll- Rand Company, New York, N.Y., a corporation of New Jersey Filed Mar. 22, 1965, Ser. No. 441,706 9 Claims. (Cl. 64-26) This invention relates to impulse tools. and more particularly to a bypass control device for such impulse tools.

Heretofore, impulse tools for applying a torque to an object and/ or for use as a source of fluid impulses for operating a tool are disclosed in U.S. Patent No. 3,116,- 617 issued January 7, 1964 to D. K. Skoog and in U.S. Patent Application Serial No. 285,160 filed March 18, 1963 by D. K. Skoog.

Conventional control devices are of the type shown in the following U.S. patents:

U.S. Patent No. Issued Inventor 1,503,618 S. G. Wingquist. S. G. Wingquist. W. B. Flanders. H. C. Johnson. 0. C. Talbot. .T. Wordsworth. C. E. Scribner. Nov. 5, 1912 H. I. Manley. Feb. 9, 1915 J. C. Hansen Ellenhammer.

June 26, 1917 W. H Hunger-lord March 11, 19l9 R. T Cooke. April 4, 1922 C. B. Funk. May 30, 192 F. Cartlidge. Dec. 14, 1926. S. G. Wingquist. June 12, 1928 S. G. Wiagquist. July 24, 1928 S. G. Wingquist. May 28, 1929. S. G. Wingquist. July 28, 1931. G. C. Magness, et a1. April 25, 1933 E. R. Monroe. April 28, 1936- F. E. Staats. Oct. 15, 1957 C. L. Graybill.

Foreign Patent Issued Inventor French 611,012"... Feb. 12, 1926 H. Haefiley. British 151,308-... Sept. 20, 1920 L. Keith. British 741,428 Dec. 7, 1955 H. C. Lee. Italian 445,487 Sept. 2, 1948 0. Maniredi.

It is the general object of the present invention to avoid and overcome difficulties of and objections to prior art practices by the provision of an improved bypass control device for an impulse tool, which bypass control device:

(1) Increases the cyclic rate of impulses per unit time without decreasing maximum torque output;

(2) Provides controlled leakage between the high pressure portion of the cavity of the impulse tool and the low pressure portion thereof only after the impulse has been delivered; and

(3) Increases power output of the tool.

The aforesaid objects of the present invention, and other objects which will become apparent as the description proceeds, are achieved by providing a bypass control device for an impulse tool for applying a torque to an object. The impulse tool has housing means provided with a cavity for sealingly containing a fluid, spindle means in the housing means and in the fluid and drive means operatively associated with one of the housing means and the spindle means for causing relative rotary movement between the housing means and the spindle means. The other of the housing means and the spindle means is adapted to engage the object. Sealing means are on one of the housing means and the spindle means. A first sealing portion is on said housing means and a second sealing portion is on said spindle Patented Nov. 8, 1966 means. The first sealing portion and the second sealing portion are in sealing relation during a relatively small portion of each revolution of the relative rotative movement. The first sealing portion and the second sealing portion and the sealing means are operable during the relative small portion of each revolution of the relative rotary movement to dynamically seal oil the cavity into a high pressure portion and a low pressure portion to produce a primary pressure pulse in the high pressure portion and on the other of the housing means and the spindle means thereby causing the other to rotate with respect to the one of the housing means and the spindle means and to apply a torque to the object. The bypass control device is in meet the housing means and the spindle means.

The bypass control device has the one being provided with cavity means in communication with the high pressure portion and the low pressure portion.

Piston means arein the cavity means and are provided with orifice means. Stop means are in the cavity means and are aligned with the orifice means. Biasing means are in the cavity means between the piston means and the stop means for normally maintaining the piston means and the stop means in spaced relation. The piston means are operative as the pressure increases in the high pressure portion, as the flow rate increases through the orifice means and as the pressure differential produced across the orifice means overcomes the biasing means to move the orifice means into engagement with the stop means thereby shutting flow of fluid between the high pressure portion and the low pressure portion. The piston means are then operative after impulse and when the biasing means overcomes the pressure differential to move away from the stop means thereby permitting flow of fluid from the high pressure portion to the low pressure portion at a rate insufiicient to move the piston means and the orifice means into engagement with the stop means with attendant substantial elimination of delay time.

For a better understanding of the present invention, reference should be had to the accompanying drawings, wherein like numerals of reference indicate similar parts throughout the several views and wherein:

FIG. 1 is aside elevational View of an impulse tool incorporating the bypass control device of the present invention, in the housing means;

FIG. 2 is a horizontal sectional view taken along the line 2,2 of FIG. 1 in the direction of the arrows;

FIG. 2A is an enlarged fragmentary view of the bypass control device;

FIG. 3 is a graph of pressure vs. time of a conventional impulse tool;

FIG. 4 is a graph similar to FIG. 3 of an impulse tool containing the bypass control device of the present invention;

FIG. 5 is a view similar to FIG. 2 showing an alternative embodiment of the bypass control device;

FIG. 6 is a view similar to FIGS. 2, 5 showing the bypass control device in the spindle means;

FIG. 7 is an enlarged fragmentary horizontal sectional view showing the orifice means disposed about the cavity means; and

FIG. 8 is a vertical sectional fragmentary view taken along the line 8-8 of FIG. 7 in the direction of the arrows.

Although the principles of the present invention are broadly applicable to power tools, the present invention is particularly adapted for use in conjunction with an impulse tool and hence it has been so illustrated and will be so described.

With specific reference to the form of the present in vention illustrated in the drawings, and referring particularly to FIGS. 1, 2, an impulse tool of the type shown dicated generally by the reference numeral 10.

This impulse tool (FIGS. 1, 2) is used for applying a torque to an object, such as a nut N. The impulse tool 10 has housing means A (FIGS. 1, 2 having center 11) provided with a cavity 12 (FIG. 2 having center 13) for sealingly containing a fluid, such as oil F. Spindle means B (having center 11) are in the housing means A and in the oil F and drive means, such as the air or electric motor D, are ope-ratively associated with one of the housing means A and the spindle means B (in this case the housing means A) for causing relative rotary movement between the housing means A and the spindle means B. The other of the housing means A and the spindle means B (Le; spindle means B) is adapted to engage the nut N by means of a socket 14 (FIG. 1) on the spindle shaft 16 (FIGS. 1', 2). Sealing means, such as the spindle blade 18 (FIG. 2) on spindle shaft 16, are on one of the housing means A and the spindle means B (in this case the spindle means B). A first sealing portion, such as the lands 20 (FIG. 2) between undercuts 22 in the housing means A, is on said housing means and a second sealing portion, such as the shank portion 24 on the spindle means B, is on said spindle means B. The lands 20 and the shank portion 24 are in sealing relation during a relatively small portion of each revolution of the relative rota-tive movement. portion 24 and the spindle blade 18 are operable during the relatively small portion of each revolution of the relative rotary movement to dynamically seal off the cavity 12 into a high pressure portion HP and a low pressure portion LP to produce a primary pressure pulse P etc. FIGS. 3, 4 in the high pressure portion HP and on the other of the housing means A and the spindle means B (i.e. spindle means B) thereby causing the spindle means B to rotate with respect to the housing means A and to apply a torque to the nut N.

The bypass control device BC (FIGS. 2, 2A) is in one of the housing means A and the spindle means B, in this case the housing means A.

BYPASS CONTROL DEVICE The bypass control device BC (FIGS. 2, 2A) has housing means A provided with cavity means, such as the cavity 26, in communication by means of passage 28 with the high pressure portion HP and passage 29 with low pressure portion LP.

Piston means, such as the piston 30, is in said cavity 26 and provided with orifice means, such as the orifice 32. Stop means, such as the stop 34, are in said cavity 26 and are aligned with the orifice 32. Biasing means, such as the spring 36, are in said cavity 26 between the piston 30 and saidstop 34 for normally maintaining the piston 30 and the stop 34in spaced relation as shown in FIGS. 2, 2A. I

The piston 30 is operative as the pressure increases in the high pressure portion HP, as the ilow rate increases through the orifice 32 and as the pressure differential produced across the orifice 32 overcomes the spring 36 to move the orifice 32 into engagement with the stop 34 (from the solid line position of FIG. 2A to the dotted line position of FIG. 2A)

As shown in FIGS. 2, 2A the stop 34 comprises the plate 38 and plunger 40, which plunger 40 shuts ofi flow of oil F between the high pressure portion HP and the low pres-sure portion LP thru passage 28.

As shown in FIGS. 2 and 2A, the stop 34 comprises the plate 38 and plunger 40, which plunger 40 shuts off The lands 20 and the shank piston 30 and the orifice 32 into engagement with the stop 34 with attendant substantial elimination of stall time i (FIG. 3).

It will be understood by referring to FIG. 3 that without the bypass control device BC of the present invention, the motor D (FIG. 1) is required to move the housing means A through the seal position, FIG. 2 (i.e., where p the spindle blade 18 and land 20 and the shank 24 and the land 20 are in contact). The motor D (FIG. 1) is now required to move the housing means A through the sealing position tending to displace oil F from the high pressure portion HP to the low pressure portion LP. Since the displaced fluid F from the high pressure portion HP to the low pressure portion LP must pass through the leakage clearances between the spindle means B, spindle blade 18, and the housing means A, a large delay time t (FIG. 3) is required for the housing means A to pass through the seal position (FIG. 2). If such leakage is zero, the delay time t is infinite.

With the improved bypass control device BC of the present invention, such bypass control device BC closes at time t (FIG. 4) and opens at time t thereby eliminating the delay time t (FIG. 3) and substantially reducing time between primary pulses P P etc, to normal acceleration time t Alternative embodiments It will be understood by those skilled in the art that alternatively as shown in FIG. 5 the stop 34 has in addition to the plate 38 and plunger 40 ball means, such as the ball 42.

Referring now to FIG. 6 the bypass control device BC is disposed in the spindle means B In FIGS. 7, 8 the housing means A is provided with orifices 44 disposed in the housing means A about the cavity 26 It will be recognized by those skilled in the art that the objects of the present invention have been achieved by providing an improved bypass control device for an impulse tool, which bypass control device:

(1) Increases the cyclic rate of impulses per unit time without decreasing the energy delivered per impulse; and

(2) Provides controlled leakage between the high pressure portion of the cavity of the impulse tool and the low pressure portion thereof after the impulse has been delivered.

While in accordance with the patent statutes preferred and alternative embodiments of the present invention have been illustrated and described in detail, it is to be particularly understood that the invention is not limited thereto or thereby.

I claim:

1. For an impulse tool for applying a torque to an object, said impulse tool having housing means provided with a cavity for sealingly containing a fluid, spindle means invsaid housing means and in said fluid, drive means operatively associated with one of said housing means and said spindle means for causing relative rotary movement between said housing means'and said spindle means, the other of said housing means and said spindle means being adapted to engage said object, sealing means on one of said housing means and said spindle means, a first sealing portion on said housing means, a second sealing portion on said spindle means, said first sealing portion and said second sealing portion being in sealing relation during a relatively small portion of each revolution of said relative rotative movement, said first sealing portion and said second sealing portion and said sealing means being operable during said relative small portion of each revolution of said relative rotary movement to dynamically seal off said cavity into a high pressure portion and a low pressure portion to produce a primary pressure pulse in said high pressure portion and on said other of said housing means and said spindle means thereby causing said other to rotate with respect to said one of said housing means and said spindle means and to apply a torque to said object; a bypass control device in one of said housing means and said spindle means, said bypass control device comprising:

(a) said one being provided with cavity means in communication with said high pressure portion and said low pressure portion,

(b) piston means in said cavity means and provided with orifice means,

(c) stop means in said cavity means and aligned with said orifice means,

(d) biasing means in said cavity means between said piston means and said stop means for normally maintaining said piston means and said stop means in spaced relation,

(e) said piston means being operative as the pressure increases in said high pressure portion, as the flow rate increases through said orifice means and as the pressure differential produced across said orifice means overcomes said biasing means to move said orifice means into engagement with said stop means thereby shutting Off flow of fluid between said high pressure portion and said low pressure portion,

(if) said piston means being operative after impulse and when said biasing means overcomes said pressure differential to move away from said stop means thereby permitting flow of fluid from said high pressure portion to said low pressure portion at a rate insuflicient to move said piston means and said orifice means into engagement with said stop means with attendant substantial elimination of stall time.

2. The bypass control device recited in claim 1 wherein said bypass control device is in said housing means.

3. The bypass control device recited in claim 1 wherein said bypass control device is in said spindle means.

with said low pressure portion.

5. The bypass control device recited in 'claim 1 wherei in said piston means is a hollow piston provided with an orifice.

6. The bypass control device recited in claim 1 wherein said stop means comprises a plate and a plunger aligned with said orifice means.

7. The bypass control device recited in claim 1 wherein said biasing means is a spring.

8. The bypass control device recited in claim 1 wherein said stop means comprises a plate, a plunger on said plate and ball means disposed between said orifice means and said plunger.

9. The bypass control device recited in claim 1 wherein said one is provided with orifice means disposed about said cavity means.

References Cited by the Examiner UNITED STATES PATENTS 1,296,769 3/1919 Cooke 6426 1,630,737 5/1927 Flandens 6426 2,953,367 9/1960 Wordsworth 64-26 X 3,116,617 1/1964 Skoog 6426 FOREIGN PATENTS 561,402 10/ 1932 Germany.

FRED C. MATTERN, JR., Primary Examiner.

H. C. COE, Assistant Examiner. 

1. FOR AN IMPULSE TOOL FOR APPLYING A TORQUE TO AN OBJECT, SAID IMPULSE TOOL HAVING HOUSING MEANS PROVIDED WITH A CAVITY FOR SEALINGLY CONTAINING A FLUID, SPINDLE MEANS IN SAID HOUSING MEANS AND IN SAID FLUID, DRIVE MEANS OPERATIVELY ASSOCIATED WITH ONE OF SAID HOUSING MEANS AND SAID SPINDLE MEANS FOR CAUSING RELATIVE ROTARY MOVEMENT BETWEEN SAID HOUSING MEANS AND SAID SPINDLE MEANS, THE OTHER OF SAID HOUSING MEANS AND SAID SPINDLE MEANS BEING ADAPTED TO ENGAGE SAID OBJECT, SEALING MEANS, ON ONE OF SAID HOUSING MEANS AND SAID SPINDLE MEANS, A FIRST SEALING PORTION ON SAID HOUSING MEANS, A SECOND SEALING PORTION ON SAID SPINDLE MEANS, SAID FIRST SEALING PORTION AND SAID SECOND SEALING PORTION BEING IN SEALING RELATION DURING A RELATIVELY SMAL PORTION OF EACH REVOLUTION OF SAID RELATIVE ROTATIVE MOVEMENT, SAID FIRST SEALING PORTON AND SAID SECOND SEALING PORTION AND SAID SEALING MEANS BEING OPERABLE DURING SAID RELATIVE SMALL PORTION OF EACH REVOLUTION OF SAID RELATIVE ROTARY MOVEMENT TO DYNAMICALLY SEAL OFF SAID CAVITY INTO A HIGH PRESSURE PORTION AND A LOW PRESSURE PORTION TO PRODUCE A PRIMARY PRESSURE PULSE IN SAID HIGH PRESSURE PORTION AND ON SAID OTHER OF SAID HOUSING MEANS AND SAID SPINDLE MEANS THEREBY CAUSING SAID OTHER TO ROTATE WITH RESPECT TO SAID ONE OF SAID HOUSING MEANS AND SAID SPINDLE MEANS AND TO APPLY A TORQUE TO SAID OBJECT; A BYPASS CONTROL DEVICE IN ONE OF SAID HOUSING MEANS AND SAID SPINDLE MEANS, SAID BYPASS CONTROL DEVICE COMPRISING: (A) SAID ONE BEING PROVIDED WITH CAVITY MEANS IN COMMUNICATION WITH SAID HIGH PRESSURE PORTION AND SAID LOW PRESSURE PORTION, (B) PISTON MEANS IN SAID CAVITY MEANS AND PROVIDED WITH ORIFICE MEANS, (C) STOP MEANS IN SAID CAVITY MEANS AND ALIGNED WITH SAID ORIFICE MEANS, (D) BIASING MEANS IN SAID CAVITY MEANS BETWEEN SAID PISTON MEANS AND SAID STOP MEANS FOR NORMALLY MAINTAINING SAID PISTON MEANS AND SAID STOP MEANS IN SPACED RELATION, (E) SAID PISTON MEANS BEING OPERATIVE AS THE PRESSURE INCREASES IN SAID HIGH PRESSURE PORTION, AS THE FLOW RATE INCREASES THROUGH SAID ORIFICE MEANS AND AS THE PRESSURE DIFFERENTIAL PRODUCED ACROSS SAID ORIFICE MEANS OVERCOMES SAID BIASING MEANS TO MOVE SAID ORIFICE MEANS INTO ENGAGEMENT WITH SAID STOP MEANS THEREBY SHUTTING OFF FLOW OF FLUID BETWEEN SAID HIGH PRESSURE PORTION AND SAID LOW PRESSURE PORTION, (F) SAID PISTON MEANS BEING OPERATIVE AFTER IMPULSE AND WHEN SAID BIASING MEANS OVERCOMES SAID PRESSURE DIFFERENTIAL TO MOVE AWAY FROM SAID STOP MEANS THEREBY PERMITTING FLOW OF FLUID FROM SAID HIGH PRESSURE PORTION TO SAID LOW PRESSURE PORTION AT A RATE INSUFFICIENT TO MOVE SAID PISTON MEANS AND SAID ORIFICE MEANS INTO ENGAGEMENT WITH SAID STOP MEANS WITH ATTENDANT SUBSTANTIAL ELIMINATION OF STALL TIME. 